Did you know that England's national curriculum no longer stipulates that, in science, secondary pupils must be taught about photosynthesis or the force of gravity? Or that, in maths, it does not specify that lessons must cover fractions? Or that, in geography, the effect of weathering processes on landscapes are no longer included?

A year after its introduction, fresh concerns are being raised about the quality of the new secondary curriculum, with warnings that pupils with less confident teachers, in particular, could find their progress hindered if they are not taught about central concepts in each subject.

The debate also appears to herald a fierce row in the run-up to the general election, with the Conservatives hinting at radical curricular reforms, should they win power. Indeed, this was a central part of shadow schools secretary Michael Gove's speech at the party's conference this month, though critics say he caricatured the debate with jibes at the new history curriculum's failure to mention Winston Churchill.

The latest entrant to the dispute is Cambridge Assessment, part of Cambridge University and the parent organisation of the examination board OCR. Cambridge Assessment is so concerned about the contents of the new curriculum, in science in particular, that it has drafted a two-page statement setting out its worries, which has been passed to Education Guardian.

The statement says: "There have been successive revisions to ... the national curriculum since its introduction two decades ago, and we are very concerned about the current direction of revision policy."

Swing away from the specific

It points out that the latest curriculum incarnation, published in 2007 and implemented from last year, has seen a drastic reduction in specified scientific content.

At key stage 3, covering the first three years of secondary school, the 1999 version of the curriculum includes 94 bullet points setting out the scientific knowledge to be taught. The 2007 version cuts this to 14 points, mainly in non-specific language.

For example, the 1999 curriculum says pupils must be taught: "the reactants in, and products of, photosynthesis"; "that the rate of photosynthesis may be limited by light intensity, carbon dioxide concentration or temperature"; and to summarise photosynthesis in a word equation. The 2007 version simply says: "life processes are supported by the organisation of cells into tissues, organs and body systems". This pattern of specified content being replaced with generalised statements occurs throughout the KS3 and KS4 science curriculum.

Cambridge Assessment's statement says: "Rather than listing key concepts and processes ... in the statutory content, the 2007 curriculum tends to focus on generalised statements of scientific activity and application. This ... threatens the notion of a clear but succinct statement of a common core of learning."

Concerns are not confined to science. In maths, required knowledge and detailed skills set out in the key stage 3 curriculum have been cut from 134 bullet points to 58. Tony Gardiner, a past president of the Mathematical Association, says: "The 2007 mathematics curriculum is 10 pages long, and they are all waffle."

The advisory committee on mathematics education, which represents the maths community in discussions with government, warned in 2007 that: "The swing from specific to descriptive wording means that it will not be clear to teachers, pupils, parents, the Qualifications and Curriculum Authority (QCA) and awarding bodies what mathematics will be taught at KS3 and KS4."

This is not a uniform trend. The government, for example, intervened in the run-up to the latest curriculum's publication to insist that lists of classic authors were retained for the teaching of English. And, despite the controversy over the omission of Churchill's name, the history curriculum stipulates the teaching of the second world war, meaning that Churchill will feature in lessons.

However, the reduction in content is part of a general move towards less government prescription over what should be taught, and has been welcomed by many. It comes after years of claims from teachers that the old curriculum was overcrowded, leaving professionals struggling to cover the ground, and with little freedom to develop individual approaches. The new curriculum is also designed to free up more time to develop links between subjects, and to give pupils more help with English and maths, should they need it.

Professor David Lambert, chief executive of the Geographical Association, says the new flexibility is welcome and good teachers would use it productively. But he adds: "The new approach is going to be hard for many teachers to pull off without a lot of training and support. I'm not sure that's there at the moment."

Critics do not necessarily advocate a return to the old-style curriculum. Tim Oates, group director of assessment research and development at Cambridge Assessment, says: "The curriculum needed to be slimmed down. But it has been done in the wrong way: research shows that the most effective curricula are sparsely stated, focused on key concepts and then giving freedom to schools to design teaching around these concepts. We have not got that. The new curriculum is just too vague." He says too much curricular space is devoted to trying to satisfy the needs of interest groups, from those promoting healthy living to the financial education lobby: the importance of pupils knowing how to manage their money is mentioned 12 times in the KS3 maths curriculum notes.

Oates also highlights a recent admission from John Crookes, of the Qualifications and Curriculum Development Agency (QCDA), that the new curricular flexibilities could widen teaching gaps between good and mediocre schools, with less confident teachers at risk of not fully taking advantages of curricular freedoms.

All of this will be seized upon by the Conservatives. In Manchester, Gove launched a stinging attack on the QCDA, claiming the science curriculum had been "debased by the bureaucrats", and pledging to restore "the proper narrative of British history" to that subject.

Positive reaction

In reality, it is suggested, most schools have not changed their curricula much since the 2007 reforms. Sue Kirkham, education policy specialist at the Association for School and College Leaders, says: "People might assume that because every word of the old curriculum is no longer spelt out, teachers will not be teaching it. But this is far from the case. The general reaction to the new curriculum has been very positive, and teachers are using the flexibilities in creative ways." The QCDA's curriculum website still includes links to the 1999 version, and supporting teaching material.

Mick Waters, the former QCA director of curriculum who led the development of the 2007 version, tells Education Guardian that a review of the effect of the new subject outlines in science and maths might be needed.

Waters, now president of the curriculum foundation charity, says: "I think that, in maths and science, there is a reasonable case to evaluate, two years after the curriculum was published, the effect it is having in these subjects.

"However, I would be hesitant to see yet another fight over what is in and what is out of the curriculum."

A QCDA spokesman says that 10,000 people were involved in consultation. He adds: "Throughout the review we were conscious of the risks inherent in a curriculum dependent upon very specific prescriptive content. Such a curriculum is unable to keep pace with a fast-changing world. The new curriculum recognises that teachers are best placed to make sure the detailed content of teaching and learning remains up-to-date, challenging and relevant."

The introduction of the first national curriculum from 1989 was dogged by a dispute between Tory ministers and their emphasis on "rigour" and "facts", and professionals who often favoured flexibility and teaching for underlying understanding. Few teachers will welcome the prospect of a repeat of this dispute, but it is on the cards if we get a new government.